Rotation Transformer for Cable Connections

ABSTRACT

The invention relates to a rotation transformer for a cable connection, one end of said cable ( 4 ) executing a limited number of revolutions in relation to the other end, about a longitudinal axis ( 1 ), whilst maintaining an uninterrupted connection between both ends. The longitudinal axis ( 1 ) comprises separation discs ( 3 ). Known rotation transformers of this type have an extremely complex technical construction. The aim of the invention is to configure a rotation transformer in such a way that it can be produced simply and cost-effectively. To achieve this, the distance between the rotatable separation discs ( 3 ) is measured in such a way that a maximum two coils of the cable ( 4 ) lie on only one plane between two separation discs ( 3 ), that the cable ( 4 ) is guided through said discs without converging and that it is fixed and wound alternately from the outer diameter to the longitudinal axis ( 1 ) and vice versa between the pairs of separation discs ( 3 ).

FIELD OF THE INVENTION

The invention relates to a rotation transformer for a cable connection.

BACKGROUND OF THE INVENTION

In the sense of this description and the claims, a cable is understoodto be any elongated, flexible, or elastic material for the transport ofenergy, information, or materials, in particular, but not exclusively,an electrical cable, an optical cable (including, for example, opticalfibers), a delivery pipe, etc.

A solution is known from JP 59.149276 in which the cable is mounted onan elastic flat spiral spring and can be rotated with the axial springend. Disadvantages of this solution include, first, its large diameterand, second, the rather large restoring moment of the rotating part inthe limiting positions and changing with the rotations.

A solution is known from DE 402 6782 in which a helical carrier body hasall inflection point and the cable is embedded and in this way guidedwith a force fit in the carrier body.

From DE 199 28 731 C2, a device for winding, unwinding, and storingelongated, flexible parts is known, which is not formed, however, as arotation transformer. This device is used for the purpose of holding acable, like in a cable drum, wherein this cable can be removed from thedrum by pulling on the two cable ends. Here, the cable has no guidanceby a bearing axis, however, and due to the only two spaces betweenadjacent separation discs, a controlled winding and unwinding, like thatrequired for a precise rotation transformer, is not possible.

DE 703 0 622 and DE 703 1 318 disclose a device for winding electricalmeasurement cables and a cable and hose box as their respectivelysubject matters. In both publications, however, the problem of rotationtransmission is not addressed in any way; instead both publications areconcerned only with the storage and release of cables, and the problemof rotating the cable ends relative to each other plays no role.

Finally, DE 40 18 440 A1 shows a spiral line arrangement which isconnected on one end to a device that can rotate back and forth about arotational axis, and on the other end to a stationary device, and whichcan rotate in or out with the rotation of the rotatable device. Thesolution proposed is technically exceedingly complicated, because asynchronizing drive for the individual cascade arrangements isnecessary.

Therefore, there is the task of constructing a rotation transformer fora cable connection that can be produced simply and cost-effectively,generates no restoring moments, requires no special drive, and places nospecial requirements on the cable configuration or embedding.

SUMMARY OF THE INVENTION

This task is achieved with the characterizing features of claim 1.Advantageous configurations follow from the subordinate claims.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is explained in more detail below withreference to the individual drawings. Shown herein are:

FIG. 1, a cross section through a rotation transformer according to theinvention;

FIG. 2, a top view of a cable winding of the rotation transformer shownin FIG. 1 between two separation discs;

FIG. 3, a cable winding of the rotation transformer shown in FIG. 1between the closest pair of separation discs;

FIG. 4, a cross section through the rotation transformer shown in FIG.1, wherein each separation disc was rotated by one more rotationrelative to FIG. 1;

FIG. 5, a representation according to FIG. 2, wherein the separationdiscs were rotated by one more rotation;

FIG. 6, a representation according to FIG. 3, wherein the separationdiscs were rotated by one more rotation;

FIG. 7, a top view of the rotation transformer in the longitudinaldirection;

FIG. 8, a cross section through a rotation transformer without a cableunder the representation of the contact lugs 5 according to FIG. 7;

FIG. 9, a representation of the passage of the cable between adjacentseparation discs.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a longitudinal axis 1, about which the entire arrangementcan rotate. On the axis 1 sit bearings 2, wherein each bearing 2 carriesa separation disc 3, preferably made from metal or plastic, and theseparation discs 3 can rotate about the bearing axis 1 independently ofeach other on the bearings 2 by means of the individual bearingarrangement. The distance of the separation discs 3 is dimensioned sothat the cable 4 lying between these discs has slight lateral play andso that it can move between the separation discs 3 without additionalmeans and is not clamped tightly by these discs, but is prevented fromforming several layers one next to the other and also there is nosignificant lateral slippage of successive windings. The separationdiscs 3 have openings, which are shown in detail in FIG. 9 and by meansof which the cable 4 can pass into the spaces between adjacentseparation discs 3. These openings are located both on the inside andalso on the outside of the separation discs 3 and the cable 4 is fedinto a space between two separation discs, so that it runs in a spiralshape from the inside to the outside, as shown in FIG. 2. Then it entersthrough the opening (not shown) in the separation disc 3 from theoutside into the space on each side of this separation disc 3 and inturn runs from the outside to the inside in a spiral shape. Thisalternating of the winding course is performed through all of theseparation disc spaces. Through this cable guidance, cable convergencewithin an intermediate space between adjacent separation discs 3 isprevented. The cable length of the binding of the cable 4 shown in FIGS.2 and 3 is dimensioned so that for a rotation of the cable feed, justone more winding is allowed into the next intermediate space relative tothe cable lead-out for each intermediate space. This state is shown inthe otherwise equal FIGS. 4, 5, and 5 [sic; 6]. Here, each separationdisc 3 has been rotated by one more rotation relative to the previousdisc.

So that this one additional rotation can be realized precisely and sothat the cable 4 is not too greatly tensioned, the separation discs 3each have on the outer periphery two contact lugs 5, as shown in FIG. 7,which are bent in alternate axial directions according to FIG. 8. Inthis way, the contact lugs 5 of each separation disc 3 allow preciselyone rotation of movement freedom relative to the adjacent separationdisc 3.

Because approximately one rotation is allowed by each individualseparation disc 3, the total number of rotations between the cablelead-in and lead-out of the rotation transformer according to theinvention is equal to the number of separation discs 3 (withoutconsideration of the housing limits).

In another not-shown variant, the cable 4 is arranged between theseparation discs 3 such that in the wound state, three or more windingsare produced. The relative rotation between the adjacent separationdiscs is then limited by an elastic sliding pad and a spiral guide pathwith corresponding rotation angle.

As mentioned above, FIG. 9 shows how the cable 4 is fixed in theseparation discs 3 by means of guide lugs 6 and is held in the axialmovement, so that the free length between the separation discs 3 remainsconstant, without bending of the cable.

1. Rotation transformer for a cable connection, wherein one end of acable (4) can execute a limited number of rotations about a longitudinalaxis (1) in relation to its other end while maintaining an uninterruptedconnection between both ends and the longitudinal axis (1), comprisingseparation discs (3), characterized in that the distance between therotatable separation discs (3) is measured in such a way that a maximumof two coils of the cable (4) lie in only one plane between twoseparation discs (3) and the cable (4) is guided through said discswithout converging and that it is fixed and wound alternately from theouter diameter to the longitudinal axis (1) and vice versa between thepairs of separation discs (3).
 2. Rotation transformer according toclaim 1, characterized in that the separation discs (3) are mounted sothat they can rotate individually on the longitudinal axis (1) and havecontact lugs (5) on their outside for limiting the maximum rotationalangle between two adjacent separation discs (3) relative to each other.3. Rotation transformer according to claim 1, characterized in that thenumber of rotations of the ends of the cable (4) is determined by thenumber of separation discs (3) and the windings stored there. 4.Rotation transformer according to claim 1, characterized in that theseparation discs (3) are mounted so that they can rotate individually onthe bearing axis (1) and can rotate relative to each other by a maximumangle, which is limited by an elastic sliding pad and a spiral guidepath.
 5. Rotation transformer according to claim 1, characterized inthat the separation discs (3) have openings with guide lugs (6), whichfix the cable (4) just strongly enough that its free length betweenadjacent separation discs (3) cannot change, but it is not damaged ornegatively affected by too strong a pressure.